2001/11/23 by Robert Robinson, Kirsi Turbedsky, Donald A. Kaiser +4 · 5 citations
Biochemistry, Genetics and Molecular Biology · Medicine · Chemistry · #Cellular Mechanics and Interactions #Cardiomyopathy and Myosin Studies #Advanced Fluorescence Microscopy Techniques #Actin #Protein filament #Actin-binding protein #Cell biology #Biophysics #Nucleation #Crystallography #Biology #Chemistry #Cytoskeleton #Biochemistry #Actin cytoskeleton
paper · doi:10.1126/science.1066333
openalex publication_date 2001/11/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We determined a crystal structure of bovine Arp2/3 complex, an assembly of seven proteins that initiates actin polymerization in eukaryotic cells, at 2.0 angstrom resolution. Actin-related protein 2 (Arp2) and Arp3 are folded like actin, with distinctive surface features. Subunits ARPC2 p34 and ARPC4 p20 in the core of the complex associate through long carboxyl-terminal alpha helices and have similarly folded amino-terminal alpha/beta domains. ARPC1 p40 is a seven-blade beta propeller with an insertion that may associate with the side of an actin filament. ARPC3 p21 and ARPC5 p16 are globular alpha-helical subunits. We predict that WASp/Scar proteins activate Arp2/3 complex by bringing Arp2 into proximity with Arp3 for nucleation of a branch on the side of a preexisting actin filament.